1. Field of the Invention
The present invention relates to a metal plate electrolyzation apparatus for electrolyzing, such as anodizing, a metal plate, and to an electrode for electrolyzing a metal plate.
2. Description of the Related Art
FIG. 5 shows an example of a conventional metal plate electrolyzation apparatus disclosed in Japanese Patent Application Publication (JP-B) No. 62-3240. FIG. 5 partially shows an anodic oxidation apparatus 110 for a belt-like aluminum plate.
In this anodic oxidation apparatus 110, an electrode 116 placed in an electrolyte 114 in an electrolytic bath 112 is connected to a cathode 118 of a power supply via a bus bar 120. Further, the electrode 116 is coupled to an electrode 122 which is positioned in parallel with the electrode 116 by an electrically conductive member 124. When an aluminum plate 126 is continuously run between the electrodes 116 and 122, anodic oxide coatings are formed on front and back surfaces of the aluminum plate 126 (so-called double side treatment).
Generally, in the metal plate electrolyzation apparatus of this type, the electrodes 116 and 122 need to be replaced after a treatment because they are worn and have deteriorated.
Since the electrodes 116 and 122 are formed integrally and are not separable in this anodic oxidation apparatus 110, the entire unit must be replaced. However, since there are generally many unillustrated structures provided within the electrolytic bath 112 in addition to the aluminum plate 126, the aluminum plate 126 and these other structures hinder replacement, and significant labor is required and costs are incurred in replacing the electrodes.
A metal plate electrolyzation apparatus of this type may be used to electrolyze only one surface of the aluminum plate 126 (so-called single side treatment). In this case, placement of an insulation sheet or an insulation plate between the unelectrolyzed surface of the aluminum plate 126 and the electrode is required, and this operation is troublesome. Further, placement or removal of the insulation member is required each time there is switching between a double side treatment and a single side treatment.
Furthermore, since the electrodes 116 and 122 are coupled by the conductive member 124 and an electric current flows to the electrode at the untreated side even in the case of a single side treatment, the flow of the electric current is more than required, resulting in low energy efficiency.
In addition, even when the above described insulation member is included, the electrode at the untreated side also essentially acts as an electrode, and an oxide coating is formed on the untreated surface of the aluminum plate 126 in the vicinity of width-direction ends thereof. As a result, the aluminum plate 126 after treatment has portions having locally increased plate thickness. When the aluminum plate 126 having these thicker portions is wound in a roll, the vicinity of the width-direction ends of the aluminum plate 126 protrude more than the other portions as the aluminum plate is being wound, forming so-called protruding edge portions. Deformation is caused at these portions, and the quality of the products may deteriorate.
Further, in a single side treatment, the degree of wear of the electrode at the untreated side is greater than that of the electrode at the untreated side. Although there is a difference between the degrees of wear of the electrodes, the entire unit including the electrode which is not worn must be replaced since the electrodes 116 and 122 are not separable. This causes waste as well as increase in production costs for electrodes.
In view of the above described facts, a task of the present invention is to obtain a metal plate electrolyzation apparatus which facilitates replacement of electrodes and allows it to be carried out at a low cost, and to obtain an electrode for electrolyzing a metal plate which is utilized in this metal plate electrolyzation apparatus. Other tasks of the present invention are to obtain a metal plate electrolyzation apparatus which facilitates switching between a single side treatment and a double side treatment, does not cause waste of electrodes nor deterioration of the quality of products in a single side treatment and has high energy efficiency, and to obtain an electrode for electrolyzing a metal plate which is utilized in this metal plate electrolyzation apparatus.
In order to solve the above described tasks, a first aspect of an electrode device relating to the present invention is a device for use in electrolyzing a metal sheet conveyed through an electrolyte along a path of travel having opposite sides, the device including: (a) a first electrode plate disposed substantially parallel to, and facing one side of the path of travel; (b) a second electrode plate disposed substantially parallel to, and facing the opposite side of the path of travel; and (c) a switching element positionable at a location electrically insulating the electrode plates from one another, and at another location for electrically connecting the electrode plates to one another.
Another aspect of an electrode device relating to the present invention is a device for use in electrolyzing a metal sheet conveyed through an electrolyte along a path of travel having opposite sides, the device including: (a) a first electrode plate disposed substantially parallel to, and facing one side of the path of travel; (b) a second electrode plate disposed substantially parallel to, and facing the opposite side of the path of travel; and (c) a fastener detachably connecting the electrodes to one another.
An aspect of an electrolyzation apparatus relating to the present invention is an apparatus for electrolyzation of a metal sheet using an electrolyte, the apparatus including: (a) a container for containing electrolyte; (b) a conveyor operable for transporting a metal sheet for electrolyzation through the container along a path of travel through electrolyte in the container, the path of travel having opposite sides; (c) a first electrode disposed substantially parallel to, and facing, one side of the path of travel; (d) a second electrode disposed substantially parallel to, and facing, the opposite side of the path of travel; (e) a switching element positionable at a location electrically insulating the electrode plates from one another, and at another location for electrically connecting the electrode plates to one another; and (f) a power source for electrically energizing the electrode plates.